1. Field of the Invention
This invention is in the field of medical devices and methods, and more particularly, directed to the use of particular light sources for diagnosis of various abnormalities, as well as for regular examinations, including procedures performed in conjunction with endoscopes, such as specula, anoscopes and sigmoidoscopes, and the like. This invention also relates to a new method for performing tissue examinations (using vaginal exams as a working example) to greatly improve the accuracy of detecting various disorders, and new devices for performing the improved exams.
2. Art Background
As used herein the phrase xe2x80x9cdiffuse lightxe2x80x9d refers to light that is transmitted omni-directionally, and the term xe2x80x9cdiffuse light sourcexe2x80x9d refers to a light source that transmits an omni-directional light.
A typical gynecological exam or gyn exam comprises the use of a speculum, a visual examination of the interior cavity and related structures, palpation of the pelvic region, and a pap smear. The visual examination is typically performed using a gooseneck lamp or even a flashlight, often without any use of magnification, although magnification has certainly been available in the medical field in other areas, such as microsurgery. There are several disadvantages to this procedure.
First, because a projecting light source is used, the ability to visualize abnormalities or areas of concern is diminished since there may be shadows or glare which distort the appearance of the area. In visual examinations where an absorption-based, photo-differentiation technique is used, such glare or, more generally, specular reflection, may completely thwart the effort to establish a more effective diagnostic procedure. More specifically, in the best-case scenario, the resultant glare mimics the reflection of light from dense or diseased nuclei, thus creating a large amount of diagnostic noise and false positives (i.e., indicating a problem when there is nothing wrong). At worst, the glare is so intense as to completely saturate the visualization/examination and prevent the examiner from identifying any cellular dysplasia whatsoever.
Second, because an external light source is used, the emitted light is not evenly disbursed which, again, may cause glare and distortion of the area under examination. Third, because the light source is incandescent, it gets hot and cannot be placed close enough to the patient without burning or uncomfortably heating the area being examined. Finally, the light spectrum of the light source (generally white light) is not the most advantageous for viewing the various abnormalities to be detected.
If the visual examination does not detect the abnormalities, a Pap smear may detect them. However, the Pap smear may be inaccurate as the analysis of a Pap smear is typically performed by an outside laboratory and relies heavily on the occurrence of an exfoliated cell from dysplastic lesions, which does not always occur. Consequently, the false negative rate for Pap smears (indicating nothing wrong, when there is a problem) has been shown to be as high as 50%.
If abnormalities are detected, the patient is brought in a second time for a more detailed examination using a colposcope. This device is a binocular microscope which is placed near the patient. A bright light (blue/green filtered white incandescent light) is supplied. The operator looks through the eyepieces of the colposcope much like looking through field glasses. This procedure is performed with a vaginal speculum or similar device in place. Some of the colposcopes have camera attachments for still picture photography.
The physician washes the area with 3-5% acetic acid and then examines the tissue for whitened areas after treatment. The acetic acid whitens tissue which is thickened, such as cancer cells. The physician also looks for clusters of blood vessels which may indicate new growth such as cancer.
The effectiveness of this colposcopy procedure in detecting abnormalities is believed to be approximately 85%, and this effectiveness is due in part to the greater degree of experience which physicians who utilize this procedure generally have. It should be noted, however, that the colposcope is difficult to use because of its size, weight, and complexity. Accordingly, it is not available in all medical facilities. It is also very expensive and not at all portable. Moreover, the procedure itself is very expensive, for both patients and medical facilities, in comparison to the Pap smear.
Because colposcopy is a specialized procedure, requiring advanced and comprehensive training on very complicated and expensive apparatus, colposcopy is typically only performed on patients who have had an abnormal screening procedure (i.e., Pap smears or other indications). Such systems have been shown to be useful in the confirmation of Pap test results, as well as in other diagnostic procedures. Various forms and variations of colposcopes are disclosed in U.S. Pat. Nos. 3,994,288; 4,134,637; 4,232,933; 4,652,103; and 4,905,670.
A number of the above-mentioned concerns were addressed by the Speculite(copyright) product, an endoscopic instrument that includes a cherniluminescent light source. The Speculite(copyright), as well as the corresponding method of use, are described in U.S. Pat. Nos. 5,179,938, and 5,329,938, assigned to The TRYLON Corporation. As explained in these patents, the chemiluminescent light source provides a portable source of illumination of the body cavity without producing any heat which could damage, or at least be uncomfortable to, the tissue in the body cavity which is being observed with the endoscopic instrument. Moreover, there is no requirement for any electrical source such as a power cord or batteries. This device also disburses light throughout the cavity being observed, rather than focusing light at a specified location.
An additional advantage of endoscopes comprising a chemiluminescent light source is that the entire instrument, including the light source, may be disposed of after use. For other (non-disposable) instruments, the latter may be sterilized, and the chemiluminescent light source disposed of and then replaced to obtain a completely sterile device.
Moreover, since the chemiluminescent light source does not require external power, the endoscopic instrument does not have to be connected to, or powered by, any electrical source and can be stored for substantial periods of time without any loss of function. As such, until the chemiluminescent light source is activated by the combination of the two chemiluminescent components, there is no loss of function. On the other hand, batteries which are used in the operation of standard electrical lights which are used in many traditional devices can deteriorate in function even when not in use over a period of time, particularly under adverse conditions such as high heat and/or humidity. Thus, although the Speculite(copyright) does have some anticipated shelf life and may, at times, be somewhat temperature sensitive, this device is nevertheless particularly useful in primitive locations where relatively high temperature and heat may be prevalent and long periods of storage may be required before the device is used as an endoscopic instrument.
The devices shown in U.S. Pat. Nos. 5,179,938 and 5,329,938 provided an endoscopic examination and viewing system that was compact, portable, disposable, shadowless, economical, and efficient. The invention also comprised a method of detection of various cellular abnormalities which was quicker, easier, more economical, simpler, more compact, and which could be performed in an office setting without the need to use colposcopy equipment.
Nevertheless, the Speculite(copyright) has drawbacks. First, because of its size, the Speculite(copyright) is not amenable to miniaturization, so that the range of endoscopic applications with the Speculite(copyright) (e.g., in surgical applications) is limited. Second, the Speculite(copyright) has a limited fuel source, so that its use as a light source is limited to a finite duration from the time the light source is ignited. Third, while the chemical components comprising the chemiluminescent light source are sealed in their capsule and are non-toxic, rupture of the capsule and spillage of the chemicals may nevertheless be a concern.
An embodiment of the present invention is directed to a modified fiber-optic light source, wherein the modification allows for the creation of a diffuse light source. The diffuse light source is comprised of an optic cable, having a diffusing element attached thereto, such that the resulting diffuse light source transmits a diffused light that may be used for illumination and/or examination of tissues (e.g., within body cavities). The diffuse light source may be used in conjunction with a speculum, as well as with other endoscopic instrumentation, such as specula, anoscopes, and the like, for application in both diagnostic and surgical procedures.
These and other features and advantages will become more apparent through the following description. It should be understood, however, that the detailed description and specific examples, while indicating particular embodiments of the invention, are given by way of illustration only and various modifications may naturally be performed without deviating from the spirit of the present invention.